Extended Data Fig. 9: Stability of Cug/PCN in C–O coupling.

a, Cycling test for the coupling of 4-iodotoluene with ethanol to form C–O bond over Cug/PCN. FTIR spectra (b), XRD pattern (c), XPS spectra (d), Cu K-edge Fourier-transformed EXAFS (e) and XANES (f) spectra of the as-prepared Cug/PCN and the catalyst recovered after nine reaction cycles.